000 AGXX40 KNHC 211023 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 623 AM EDT WED SEP 21 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. PERSISTENT DEEP LAYERED TROUGH HAS DRIFTED WWD PAST 24 HOURS AND NOW FROM SE LOUISIANA COAST TO NEAR 23N93W WITH ACTIVE CONVECTION OCCURRING ON SE SIDE OF ATTENDANT UPPER TROUGH. FEATURES FORECAST TO SHIFT WWD AND INLAND ACROSS S TEXAS AND MEXICO TONIGHT. OTHERWISE...WEAK HIGH PRES IN THE N CENTRAL GULF WILL DRIFT SLOWLY E THROUGH THE WEEKEND. FAIRLY BENIGN MARINE CONDITIONS ARE EXPECTED TO CONTINUE WITH GENTLE TO LIGHT WINDS AND SEAS 2 FT OR LESS. WINDS WILL INCREASE IN THE WESTERN GULF FRI THROUGH SUN AS THE PRES GRADIENT TIGHTENS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS. CENTRAL ATLC RIDGE IS ALONG 35N AND BLOCKED FROM BUILDING INTO THE REGION WITH DEEP LAYERED TROUGHING FROM NEAR BERMUDA SW TO CENTRAL BAHAMAS SLOWLY WEAKENING. LIGHT TO MODERATE TRADES PERSIST ACROSS THE BASIN W OF 60W WITH SEAS GENERALLY 5 FT OR LESS...EXCEPT FOR STRONG NE TO E WINDS TO AROUND 20 KT ACROSS S CENTRAL PORTIONS AND ALONG THE NW COAST OF COLOMBIA...WHERE SEAS REMAIN LESS THAN 8 FT. A WEAK TROPICAL WAVE ACROSS THE CENTRAL CARIB IS BECOMING MORE DIFFICULT TO FOLLOW AND ASSOCIATED MOISTURE HAS LARGELY SHIFTED WNW ACROSS HISPANIOLA AND INTO E CUBA. HAVE THUS DROPPED THIS WAVE FROM PROGS AND UPPER LOW SHIFTING SLOWLY WESTWARD ACROSS THE W CENTRAL CARIB IS THE MAIN FORCING FEATURE FOR CONVECTION. DIMINISHED CONDITIONS ASSOCIATED WITH T.D. KARL ARE BRUSHING ACROSS N PORTIONS OF TROPICAL N ATLC WATERS...WHILE NE SWELL IS MOVING THROUGH NE CARIB PASSAGESBUT REGISTERING AT 2-4 FT AT 11-12 SECS PER FEW BUOYS OBS. WWD MOTION OF THE WEAKENED KARL WILL BRING MORE WEATHER THAN PREVIOUSLY EXPECTED TO THESE NRN ZONES AND LEEWARDS NEXT 24 HOURS BEFORE KARL MAKES THE LONG AWAITED NW TURN AND BEGINS TO LIFT OUT OF THE NE CARIB REGION FRI. ONCE KARL BEGINS THIS NW MOTION...LITTLE SWELL ENERGY IS EXPECTED TO PROPAGATE SW ACROSS THE NE CARIBBEAN. STRONG TRADES TO RETURN TO S CENTRAL PORTIONS SAT AND SUN WITH NOCTURNAL PEAK AS KARL LIFTS OUT AND ATLC RIDGE NOSES INTO NE CARIB BETWEEN KARL AND LISA. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS. A DEEP LAYERED LOW TO MIDDLE LEVEL TROUGH EXTENDS FROM NW OF BERMUDA TO THE NW BAHAMAS AND HAS DRIFTED NW PAST 24 HOURS...WITH WEAKENING ATTENDANT LLVL TROUGH LINGERING BELOW. THIS TROUGHING WILL DRIFT NW OVER THE NEXT 24-48 HRS AND BECOME DIFFUSE WHILE CONTINUING TO ACT AS A CONVERGENCE ZONE FOR AREAS OF CONVECTION. THE REMNANTS OF JULIA CONTINUE ACROSS THE COASTAL CAROLINAS WITH TROUGHING EXTENDING S THEN SSW INTO NE FLORIDA AND IS ALSO INTERACTING WITH ABOVE UPPER TROUGH FOR ACTIVE CONVECTION ACROSS CAPE CANAVERAL AREA. MODELS SUGGEST VORTICITY ASSOCIATED WITH JULIA REMNANTS WILL DRIFT S WITH LLVL TROUGH NEXT 24-36 HOURS AND SLOWLY WEAKEN. JULIA WILL JUST NOT DIE! MEANWHILE...KARL CONTINUES TO STRUGGLE WITH REMNANT LLCC MOVING WWD PAST 18-24 HOURS AND WILL GRADUALLY TURN WNW TODAY AND MORE NW TONIGHT INTO THU. ELY SWELL AHEAD OF BROAD NRN SEMICIRCLE WIND FIELD OF KARL HAS MOVED INTO SE AND E WATERS PAST 24 HOURS AND WILL CONTINUE W TO 80W AND FLORIDA COASTS TONIGHT THROUGH SAT NIGHT BEFORE BEGINNING TO FADE. THE LAST NHC FORECAST MOVES KARL ACROSS E PORTIONS OF AMZ121 AND 115 THU THROUGH EARLY SAT...AS IT RECURVES AND FINALLY BEGINS TO INTENSIFY TO A FORMIDABLE TROPICAL STORM. A WEAK PRES PATTERN TO THE W AND SW OF KARL WILL PRODUCE LIGHT TO MODERATE WINDS AND SMOOTH SEAS...DOMINATED BY SWELL FROM KARL. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... TROPICAL STORM WARNING THU NIGHT. .AMZ121...ATLANTIC FROM 22N TO 27N BETWEEN 65W AND 70W... TROPICAL STORM WARNING THU INTO THU NIGHT. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER STRIPLING. NATIONAL HURRICANE CENTER.